Move kernel baseline tests to front_end.

pkg/front_end/testcases/arithmetic.dart.outline.expect

Index: pkg/front_end/testcases/arithmetic.dart.outline.expect
diff --git a/pkg/front_end/testcases/arithmetic.dart.outline.expect b/pkg/front_end/testcases/arithmetic.dart.outline.expect
new file mode 100644
index 0000000000000000000000000000000000000000..005581f66a8349e2fec9c73d12ca2aed9201f64e
--- /dev/null
+++ b/pkg/front_end/testcases/arithmetic.dart.outline.expect
@@ -0,0 +1,10 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+static method foo(core::int x, core::int y) → core::int
+  ;
+static method loop(core::List<dynamic> xs) → void
+  ;
+static method main() → dynamic
+  ;